Roof or floor construction



Nov. 30 ,1926. 1,608,987

H. E. MARKS ET AL ROOF OR FLOOR CONSTRUCTION Filed August 30 9 FEG..1.

Patented Nov. 30, 1926.

UNITED STATES PATENT OFFICE.

HERBERT E. MARKS, OF SEWICKLEY, PENNSYLVANIA, AND JOSEPH '1. O'NEILL, OF CHICAGO, ILLINOIS.

ROOF OR FLOOR CONSTRUCTION.

Application filed August 30, 1924. Serial No. 735,082.

This invention relates to roof and like constructions composed of monolithic slabs of cementitious material, such as gypsum, cement, and the like. The object is to provide a roof construction of this kind which thoroughly insulates the metallic supporting members and thus prevents the frost from striking through and causing sweating at such metallic supporting members, and at the same time provides a roof structure which is of light weight and comparatively cheap to construct.

Roof structures of cementitious slabs, substantially monolithic, as heretofore constructed, are characterized by the fact that the main portion of the body of the slab was located below the tops of the metal supporting bars, with only a r'elatively thin layer of cementitious material over such bars. The result is that in the winter time the cold penetrates the thin layer of cementitious material above the metallic bars, causing sweating and discoloration of the exposed lower portions of said metallic bars. To overcome this to some degree the slabs are made quite thick, to provide a greater depth of cementitious material above the tops of the metallic bars, but this adds to the Weight and cost of the roof.

Our invention has for its purpose to provide a roof construction of the character described in which the metallic supporting bars are thoroughly insulated from the cold, without the necessity of a very thick body of cementitious material, thus reducing the weight and cost of construction of the roof. Generally stated, the invention consists in supporting the monolithic cementitious slab entirely on the tops of the metallic bars.

In the accompanying drawing showing one embodiment of our invention Fig. 1 1s 1 a perspective view showing the roof members prior to pouring the cementitious material, Fig. 2 is a vertical sectional view of the completed roof; and Figs 3 and at are detail views illustrating two forms of means for anchoring the slab to the supporting bars.

In the drawings 1 indicates frame mem bers which may be the purlins or other beams of the main roof structure, and which may be either I-beams or channel bars.

Supported on these frame members and suitably secured thereto and extending transversely thereof are .a series of bars 2 spaced appropriate distances apart and form What may be termed the rafters of the roof construction. These may be of various constructions, such as channel bars, I-bars, or light section rails as shown, that is, bars having a wide flanged base and a more or less bulbous head. These bars are spaced the desired distances apart and will be of the necessary strength to carry the weight of the monolithic slab and transfer. it to the main beams 1. Supported on the tops or heads of these bars are suitable composition boards 3, such as plaster boards, which will be of a length (or a width) extending from center to center of adjacent bars 2. If this space is such that under the load of the poured cementitious material these composition boards are liable to sag, a temporary showing or support will be provided, to be removed when the cementitious material has set. Placed on top of the plaster boards, and preferably extending transversely of the bars2, is a suitable metallic reinforcing fabric, preferably that known as welded metal mesh comprising longitudinal or strand wires 4 and transverse wires 5, welded together at their crossing points. This is laid directly on the plaster board, in straight and flat condition. The body of the slab 6 is formed of suitable cementitious material, such as gypsum or the like, is poured directly upon the reinforcing fabric and composition boards described, and in setting bonds to the composition boards so that the latter form the permanent lower surface of the slab; and the reinforcing fab- I ric lies well down in the tension zone of the slab, thus providing an efficient reinforcement. The resultant structure is a mono lithic slab supported on the tops of the supporting bars 2, and thus providing above the tops of these metallic bars 2 a thickness of insulating material equal to the thickness of the slab. As a result the cold cannot penetrate through and cause sweating of the bars 2. Since the slabs rest entirely on the tops of the bars 2, they can be of minimum thickness and need not be of the thickness adopted in prior constructions in order to provide a sufficient thickness of insulating material above the bars. The usual waterproofing coating can be applied to the to surface of the slab, if necessary or desire,

The construction described can be applied to roofs of any character, either flat or sloping. In order to secure the slab to the supporting bars 2, to prevent it from lifting, and, in the case of sloping roofs, to prevent it from slipping, suitable anchoring means engaging the bars 2 and extending up into the slab are provided. Various forms of devices for this purpose may be used, the drawings showing two forms suitable for this purpose. The anchoring device shown in Fig. 3 comprises a strap or band of metal 7 which extends entirely around and underneath the bar 2 and has its ends extending up between two adjacent composition boards 3, with one of said ends bent or looped over to receive the other end, as shown at 8, such upstanding ends being provided with aligning holes through which is inserted a transverse or lateral member or pin 9, lying fairly well up in the cementitious body 6 and above the metal reinforcement 4, thus providing a firm anchorage in the slab. This member manifestly ties the slab to the supporting bars and prevents the slab from lifting and also from sliding on said bars. They also prevent the boards or plates 3 from sliding or slipping upon their supporting bars 2.

The anchoring means shown in Fig. 4 comprises two similar members 10, formed either of strap or band metal or heavy wire or the like, having their lower portions bent to engage the head of the bar 2 and having portions extending up between adjacent composition boards 3 and their upper ends turned laterally, as at 11, to provide the anchorage in the body of the slab as above described. Various other forms of anchoring devices ,will readily suggest themselves to the skilled worker.

The roof described is easy and cheap of erection, permits of amin1mum thickness of slab and is thus light and comparatively cheap, and at the same time thoroughly insulates the metal supporting members.

We claim:

1. A roof or like structure of the character described, comprising frame members, bars supported in interspaced relation transversely on the frame members, composition boards supported on the tops of said bars, metal reinforcing fabric above said composition boards, a cementitious body molded in place on the composition boards and embedding and being reinforced by said fabric, and anchoring means engaging said bars and projecting up into said slab and anchored in the body thereof.

2. A roof or like structure of the character described, comprising frame members, bars supported in interspaced relation trans versely on the frame members, composition boards supported on the tops of said bars, metal reinforcing fabric above said composition boards, a cementitious body molded in place on the composition boards and embedded and being reinforced by said fabric, and anchoring means engaging said bars and extending up between adjacent composition boards and provided with laterally extending portions lying in said cementitious body.

3. A roof or like structure of the character described, comprising frame members, metal flanged bars supported in interspaced relation transversely on the frame members, a monolithic cementitious slab on said bars and lying above the tops thereof, continuous metal reinforcing fabric extending transversely of the bars and embedded in and reinforcing said cementitious slab, and anchoring members engaging said bars and extending up into and being anchored in said slab.

In testimony whereof, we sign our names.

HERBERT E. MARKS. JOSEPH T. ONEILL. 

